Looking to mod, but really confused

[The~Skater~187]

In km looking to root, install twrp and flash aftermarket roms AMD custom kernels, but am extremely confused. I already bricked one sm-g960u. Now that I have my new phone, I don't want to screw this one up and have to go back to my S5.
My replacement came fully updated to latest android 10, no OEM unlock option in developers options. Phone is a sprint locked S9 on Boost Mobile. Not sure if it helps.
Any help would be awesome. I attached some pics of system info to better help anyone guide me correctly to my desired goal (or as close as I can get).

Thanks in advance for your time and any help provided.

 

[TheMadScientist]

In km looking to root, install twrp and flash aftermarket roms AMD custom kernels, but am extremely confused. I already bricked one sm-g960u. Now that I have my new phone, I don't want to screw this one up and have to go back to my S5.
My replacement came fully updated to latest android 10, no OEM unlock option in developers options. Phone is a sprint locked S9 on Boost Mobile. Not sure if it helps.
Any help would be awesome. I attached some pics of system info to better help anyone guide me correctly to my desired goal (or as close as I can get).

Thanks in advance for your time and any help provided.

You have a locked bootloader. If you want Roms and twrp you need a different device.

 

[The~Skater~187]

You have a locked bootloader. If you want Roms and twrp you need a different device.

I thought I had read that root and twrp was still possible?

Sent from my SM-G960U using Tapatalk

 

[TheMadScientist]

I thought I had read that root and twrp was still possible?

Sent from my SM-G960U using Tapatalk

Root is possible on 8.0 only. No twrp. 80 % charge limit. If you look down in the snap dragon threads b section. You can find ir